﻿<!DOCTYPE html>
<html>
<head>
  <title>Snap Link Reshaping</title>
  <!-- Copyright 1998-2021 by Northwoods Software Corporation. -->
  <meta name="description" content="When reshaping an orthogonal link, make sure the points are moved onto a grid." />
  <meta name="viewport" content="width=device-width, initial-scale=1">

  <script src="../release/go.js"></script>
  <script src="Figures.js"></script>
  <script src="SnapLinkReshapingTool.js"></script>
  <script src="../assets/js/goSamples.js"></script>  <!-- this is only for the GoJS Samples framework -->
  <script id="code">
    function init() {
      if (window.goSamples) goSamples();  // init for these samples -- you don't need to call this
      var $ = go.GraphObject.make;  // for conciseness in defining templates

      myDiagram =
        $(go.Diagram, "myDiagramDiv",  // must name or refer to the DIV HTML element
          {
            // supply a simple narrow grid that manually reshaped link routes will follow
            grid: $(go.Panel, "Grid",
              { gridCellSize: new go.Size(8, 8) },
              $(go.Shape, "LineH", { stroke: "lightgray", strokeWidth: 0.5 }),
              $(go.Shape, "LineV", { stroke: "lightgray", strokeWidth: 0.5 })
            ),
            "draggingTool.isGridSnapEnabled": true,
            linkReshapingTool: $(SnapLinkReshapingTool),
            // when the user reshapes a Link, change its Link.routing from AvoidsNodes to Orthogonal,
            // so that combined with Link.adjusting == End the link will retain its reshaped mid points
            // even after nodes are moved
            "LinkReshaped": function(e) { e.subject.routing = go.Link.Orthogonal; },
            "animationManager.isEnabled": false,
            "undoManager.isEnabled": true
          });

      // when the document is modified, add a "*" to the title and enable the "Save" button
      myDiagram.addDiagramListener("Modified", function(e) {
        var button = document.getElementById("SaveButton");
        if (button) button.disabled = !myDiagram.isModified;
        var idx = document.title.indexOf("*");
        if (myDiagram.isModified) {
          if (idx < 0) document.title += "*";
        } else {
          if (idx >= 0) document.title = document.title.substr(0, idx);
        }
      });

      // Define a function for creating a "port" that is normally transparent.
      // The "name" is used as the GraphObject.portId, the "spot" is used to control how links connect
      // and where the port is positioned on the node, and the boolean "output" and "input" arguments
      // control whether the user can draw links from or to the port.
      function makePort(name, spot, output, input) {
        // the port is basically just a small transparent square
        return $(go.Shape, "Circle",
          {
            fill: null,  // not seen, by default; set to a translucent gray by showSmallPorts, defined below
            stroke: null,
            desiredSize: new go.Size(7, 7),
            alignment: spot,  // align the port on the main Shape
            alignmentFocus: spot,  // just inside the Shape
            portId: name,  // declare this object to be a "port"
            fromSpot: spot, toSpot: spot,  // declare where links may connect at this port
            fromLinkable: output, toLinkable: input,  // declare whether the user may draw links to/from here
            cursor: "pointer"  // show a different cursor to indicate potential link point
          });
      }

      myDiagram.nodeTemplate =
        $(go.Node, "Spot",
          { locationSpot: go.Spot.Center },
          new go.Binding("location", "loc", go.Point.parse).makeTwoWay(go.Point.stringify),
          { selectable: true },
          { resizable: true, resizeObjectName: "PANEL" },
          // the main object is a Panel that surrounds a TextBlock with a Shape
          $(go.Panel, "Auto",
            { name: "PANEL" },
            new go.Binding("desiredSize", "size", go.Size.parse).makeTwoWay(go.Size.stringify),
            $(go.Shape, "Rectangle",  // default figure
              {
                portId: "", // the default port: if no spot on link data, use closest side
                fromLinkable: true, toLinkable: true, cursor: "pointer",
                fill: "white"  // default color
              },
              new go.Binding("figure"),
              new go.Binding("fill")),
            $(go.TextBlock,
              {
                font: "bold 11pt Helvetica, Arial, sans-serif",
                margin: 8,
                maxSize: new go.Size(160, NaN),
                wrap: go.TextBlock.WrapFit,
                editable: true
              },
              new go.Binding("text").makeTwoWay())
          ),
          // four small named ports, one on each side:
          makePort("T", go.Spot.Top, false, true),
          makePort("L", go.Spot.Left, true, true),
          makePort("R", go.Spot.Right, true, true),
          makePort("B", go.Spot.Bottom, true, false),
          { // handle mouse enter/leave events to show/hide the ports
            mouseEnter: function(e, node) { showSmallPorts(node, true); },
            mouseLeave: function(e, node) { showSmallPorts(node, false); }
          }
        );

      function showSmallPorts(node, show) {
        node.ports.each(function(port) {
          if (port.portId !== "") {  // don't change the default port, which is the big shape
            port.fill = show ? "rgba(0,0,0,.3)" : null;
          }
        });
      }

      myDiagram.linkTemplate =
        $(go.Link,  // the whole link panel
          { relinkableFrom: true, relinkableTo: true, reshapable: true, resegmentable: true },
          {
            routing: go.Link.AvoidsNodes,  // but this is changed to go.Link.Orthgonal when the Link is reshaped
            adjusting: go.Link.End,
            curve: go.Link.JumpOver,
            corner: 5,
            toShortLength: 4
          },
          new go.Binding("points").makeTwoWay(),
          // remember the Link.routing too
          new go.Binding("routing", "routing", go.Binding.parseEnum(go.Link, go.Link.AvoidsNodes))
            .makeTwoWay(go.Binding.toString),
          $(go.Shape,  // the link path shape
            { isPanelMain: true, strokeWidth: 2 }),
          $(go.Shape,  // the arrowhead
            { toArrow: "Standard", stroke: null })
        );

      load();  // load an initial diagram from some JSON text

      var link = myDiagram.links.first();
      if (link) link.isSelected = true;

      // initialize the Palette that is on the left side of the page
      myPalette =
        $(go.Palette, "myPaletteDiv",  // must name or refer to the DIV HTML element
          {
            maxSelectionCount: 1,
            nodeTemplateMap: myDiagram.nodeTemplateMap,  // share the templates used by myDiagram
            model: new go.GraphLinksModel([  // specify the contents of the Palette
              { text: "Start", figure: "Circle", fill: "green" },
              { text: "Step" },
              { text: "DB", figure: "Database", fill: "lightgray" },
              { text: "???", figure: "Diamond", fill: "lightskyblue" },
              { text: "End", figure: "Circle", fill: "red" },
              { text: "Comment", figure: "RoundedRectangle", fill: "lightyellow" }
            ])
          });

      document.getElementById("AvoidsNodesCheckBox").onclick = function(e) {
        myDiagram.toolManager.linkReshapingTool.avoidsNodes = e.target.checked;
      }
    }


    // Show the diagram's model in JSON format that the user may edit
    function save() {
      saveDiagramProperties();  // do this first, before writing to JSON
      document.getElementById("mySavedModel").value = myDiagram.model.toJson();
      myDiagram.isModified = false;
    }
    function load() {
      myDiagram.model = go.Model.fromJson(document.getElementById("mySavedModel").value);
      loadDiagramProperties();
    }

    function saveDiagramProperties() {
      myDiagram.model.modelData.position = go.Point.stringify(myDiagram.position);
    }
    // Called by "InitialLayoutCompleted" DiagramEvent listener, NOT directly by load()!
    function loadDiagramProperties(e) {
      // set Diagram.initialPosition, not Diagram.position, to handle initialization side-effects
      var pos = myDiagram.model.modelData.position;
      if (pos) myDiagram.initialPosition = go.Point.parse(pos);
    }
  </script>
</head>
<body onload="init()">
<div id="sample">
  <div style="width: 100%; display: flex; justify-content: space-between">
    <div id="myPaletteDiv" style="width: 105px; height: 620px; margin-right: 2px; background-color: whitesmoke; border: solid 1px black"></div>
    <div id="myDiagramDiv" style="flex-grow: 1; height: 620px; border: solid 1px black"></div>
  </div>
  <label><input type="checkbox" id="AvoidsNodesCheckBox" checked="checked"/>avoidsNodes</label>
  <p>
    This sample is a simplified version of the <a href="../samples/draggableLink.html">Draggable Link</a> sample.
    Links are not draggable, there are no custom <a>Adornment</a>s, nodes are not rotatable, and links
    do not have text labels.
  </p>
  <p>
    Its purpose is to demonstrate the <a href="SnapLinkReshapingTool.js">SnapLinkReshapingTool</a>,
    an extension of <a>LinkReshapingTool</a> that snaps each dragged reshape handle of selected Links to
    the nearest grid point.  If the <a>SnapLinkReshapingTool.avoidsNodes</a> option is true,
    as it is by default, then the reshaping is limited to points where the adjacent segments would not
    be crossing over any avoidable nodes.
  </p>
  <p>
    Note how the "LinkReshaped" DiagramEvent listener changes the <a>Link.routing</a> of the reshaped Link,
    so that it is no longer AvoidsNodes routing but simple Orthogonal routing.
    This combined with <a>Link.adjusting</a> being End permits the middle points of the link route to be
    retained even after the user moves or resizes nodes.
    Furthermore there is a TwoWay <a>Binding</a> on <a>Link.routing</a>, so that the model remembers
    whether the link route had ever been reshaped manually.
  </p>
  <button id="SaveButton" onclick="save()">Save</button>
  <button onclick="load()">Load</button>
  <textarea id="mySavedModel" style="width:100%;height:300px">
{ "class": "go.GraphLinksModel",
  "linkFromPortIdProperty": "fromPort",
  "linkToPortIdProperty": "toPort",
  "modelData": {"position":"0 0"},
  "nodeDataArray": [
{"text":"DB", "figure":"Database", "fill":"lightgray", "key":-3, "loc":"184 176"},
{"text":"DB", "figure":"Database", "fill":"lightgray", "key":-2, "loc":"248 248"},
{"text":"DB", "figure":"Database", "fill":"lightgray", "key":-4, "loc":"424 192"},
{"text":"DB", "figure":"Database", "fill":"lightgray", "key":-5, "loc":"320 152"},
{"text":"DB", "figure":"Database", "fill":"lightgray", "key":-6, "loc":"424 320"},
{"text":"DB", "figure":"Database", "fill":"lightgray", "key":-7, "loc":"352 256"},
{"text":"DB", "figure":"Database", "fill":"lightgray", "key":-8, "loc":"176 296"},
{"text":"DB", "figure":"Database", "fill":"lightgray", "key":-9, "loc":"288 344"},
{"text":"Step", "key":-10, "loc":"96 240"},
{"text":"Step", "key":-11, "loc":"536 280"}
 ],
  "linkDataArray": [
{"from":-10, "to":-11, "fromPort":"R", "toPort":"L", "points":[121,240,131,240,132,240,132,240,216,240,216,176,264,176,264,104,392,104,392,240,480,240,480,280,501,280,511,280], "routing":"Orthogonal"}
  ]}
  </textarea>
</div>
</body>
</html>
